Chemical treatment, plating, and residue elimination method

ABSTRACT

By means of a pump for supplying a processing fluid such as a plating fluid to a closed processing cup such as a closed plating cup, at least either the pressure or flow rate of the processing fluid or plating fluid circulating within the closed processing cup or the closed plating cup is cyclically changed. Further, the direction of circulation of the processing fluid circulating within the closed processing cup is also changed cyclically. Under a method of manufacturing a semiconductor device and a method of manufacturing a printed board, a semiconductor wafer and a printed board are disposed in the closed plating cup such that blind holes formed by closing openings on one end of via holes or openings on one end of through holes are brought into contact with a circulating plating fluid, thereby eliminating air bubbles that remain. As a result, a manufacturing yield or performance of a product is improved.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a plating system and method forplating a member to be plated through use of a closed-type plating cup,to a method of manufacturing a semiconductor device using the platingsystem and method, and further to a method of manufacturing a printedboard using the plating method and system.

[0003] 2. Background Art

[0004] A semiconductor device is constituted of, for example, asemiconductor substrate made of a group IV compound such as silicon or agroup III-V compound such as gallium arsenide (GaAs). Via holes areformed to penetrate through a semiconductor substrate so as to feedpower to a semiconductor substrate of a completed semiconductor deviceor so as to impart the ground potential to the semiconductor substrate.The interior surface of each of the via holes is often plated with gold(Au) or the like. Processes of manufacturing the semiconductor deviceinclude a plating process of plating a semiconductor wafer before thewafer is sliced into a plurality of semiconductor chips. In each of thesemiconductor chips, a via hole is formed. In the plating process, aplating layer is formed on the interior surface of each of the via holeswhile one of the ends of each via hole is closed; that is, each of thevia holes is held as a blind hole.

[0005] In a process of manufacturing a semiconductor device having sucha via hole, the via hole is formed through, e.g., reactive ion etching.Residues, such as organic polymer including carbon, or chlorine producedduring the course of reactive ion etching, remain on the interiorsurface of the via hole formed through reactive ion etching. For thisreason, the process includes a residue elimination process foreliminating the residues. Further, the process includes an electrolessplating process of forming a feeding layer on the interior surfaces ofthe via holes through electroless plating before a plating layer isformed on the interior surfaces of the via holes from which the residueshave been removed.

[0006] In a multilayer printed board, through holes are formed in aprinted board. A plating layer of copper (Cu) or the like is formed onthe surface of each of the through holes, including an interior surface.The plating layer is used for interlayer connection between layers of amultilayer printed board. In some cases, through holes formed in theprinted board are also plated while one end of each of the through holesis closed; that is, the through holes are held in the state of blindholes.

[0007] When a plating layer is formed on a blind hole of the printedboard, the manufacturing process also includes an electroless platingprocess for forming a plating layer on the interior surface of the blindhole through electroless plating.

[0008] A plating system having a closed plating cup is usually used foreffecting the foregoing plating operation. The closed plating cupsubjects a semiconductor wafer or a printed board to electrolyticplating, by means of circulating a plating fluid at a certain pressureand at a certain flow rate within a closed internal processing chamber.A member to be plated, such as a semiconductor wafer or a printed board,is disposed within the closed plating cup such that open ends ofrespective via holes or through holes are oriented faceup. A platinglayer is formed on the surface of each of the blind holes, including aninterior surface, by means of electrolysis of the plating fluid.

[0009] A treatment system having a closed-type processing cup is usuallyused in the process of eliminating residues from via holes of asemiconductor device, in the electroless plating process, and in theprocess of subjecting a printed board to electroless plating. Theclosed-type processing cup eliminates residues from via holes of asemiconductor wafer, effects electroless plating, and subjects throughholes of the printed board to electroless plating, by means ofcirculating a treatment fluid through a closed internal processingchamber at a certain pressure and flow rate. The treatment is effectedin a face-up style in which the semiconductor wafer and the printedboard are subjected to treatment while their via holes and through holesare oriented upward. Moreover, the semiconductor wafer and the printedboard are disposed in the closed-type processing cup such that theopenings are brought into contact with the circulating treatment fluid.As a result of the via holes and through holes being brought intocontact with the treatment fluid, elimination of residues from surfaces,including the interior surfaces of the blind holes, and formation of anelectroless plating layer are performed.

[0010] In relation to a plating operation for forming a plating layer onthe surface of such a blind hole, including an interior surface, airbubbles arising in the blind hole pose a problem. A faceup style iseffective for diminishing the amount of air bubbles arising in a blindhole. However, despite adoption of the faceup style, a problem of airbubbles still remains unsolved. Particularly when the aspect ratio of ablind hole becomes higher such that hole depth becomes greater than holediameter, occurrence of air bubbles in a blind hole cannot be avoided.If air bubbles remain in the same location, a plating fluid fails tocome into contact with a portion of the interior surface correspondingto the location. Consequently, failures arise in the plating layer. Theplating failures result in disconnection of a plating layer or anincrease in electric resistance. In turn, this accounts for a drop-offin manufacturing yield or for deterioration of performance of acompleted semiconductor device or printed board.

SUMMARY OF THE INVENTION

[0011] The present invention proposes a chemical treatment system, achemical treatment method, and a residue elimination method, which areimproved so as to enable performance of such residue eliminationtreatment, formation of an electroless plated layer, and inhibition ofoccurrence of deficiencies in an electrochemically-plated layer.

[0012] The present invention proposes a plating system and a platingmethod which have been improved so as to be able to prevent occurrenceof plating failures.

[0013] The present invention proposes a method of manufacturing animproved semiconductor device and a method of manufacturing a printedboard, which methods are improved so as to be able to hamper occurrenceof plating failures.

[0014] According to one aspect of the present invention, a chemicaltreatment system comprises a closed processing cup, a fluid reservoirtank and a pump for supplying the treatment fluid. The closed processingcup subjects a member to be treated to chemical treatment whilecirculating therein a treatment fluid at a certain pressure and acertain flow rate. The fluid reservoir tank stores the treatment fluid.The pump supplies the treatment fluid from the fluid reservoir tank tothe closed processing cup, wherein the pump periodically changes atleast either the pressure or flow rate of the treatment fluid in theclosed processing cup.

[0015] In another aspect of the present invention, in the chemicaltreatment system, the pump is preferably constituted of a pulsatingpump, and the pulsating pump periodically changes at least either thepressure or flow rate of the treatment fluid in the closed processingcup.

[0016] In another aspect of the present invention, the chemicaltreatment system preferably further comprises a supply channel forsupplying the treatment fluid to the closed processing cup, a dischargechannel for discharging the treatment fluid from the closed processingcup, and a flow throttle valve provided in the discharge channel.

[0017] According to another aspect of the present invention, a chemicaltreatment system comprises a closed processing cup, a fluid reservoirtank and a pumping apparatus for supplying the treatment fluid. Theclosed processing cup subjects a member to be treated to chemicaltreatment while circulating therein a treatment fluid at a certainpressure and a certain flow rate. The fluid reservoir tank stores thetreatment fluid. The pumping apparatus supplies the treatment fluid fromthe fluid reservoir tank to the closed processing cup, wherein theflowing direction of the treatment fluid within the closed processingcup is periodically changed.

[0018] In another aspect of the present invention, in the chemicaltreatment system, the closed processing cup has preferably first andsecond treatment fluid flow ports, and the pumping apparatus haspreferably first and second pumps. Further, the first pump circulatesthe treatment fluid in the closed processing cup from the firsttreatment fluid flow port to the second treatment fluid flow port, andthe second pump circulates the treatment fluid in the closed processingcup from the second treatment fluid flow port to the first treatmentfluid flow port.

[0019] In another aspect of the present invention, the chemicaltreatment preferably further comprises a first treatment fluid channelto be connected to the first treatment fluid flow port of the closedprocessing cup and a second treatment fluid channel to be connected tothe second treatment fluid flow port of the closed processing cup. Afirst flow regulation valve is provided in the first treatment fluidflow channel; and a second flow regulation valve provided in the secondtreatment fluid flow channel. When the treatment fluid flows from thefirst treatment fluid flow port to the second treatment fluid flow portin the closed processing cup, the second flow regulation valve providedin the second treatment fluid flow channel connected to the secondtreatment fluid flow port is taken as a flow throttle valve, and whenthe treatment fluid flows from the second treatment fluid flow port tothe first treatment fluid flow port, the first flow regulation valveprovided in the first treatment fluid flow channel connected to thefirst treatment fluid flow port is taken as a flow throttle valve.

[0020] Other and further objects, features and advantages of theinvention will appear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a view showing the overall configuration of a chemicalprocessing system (or a plating system) according to the presentinvention.

[0022]FIG. 2 shows an example of a configuration of a closed-typeprocessing cup (or a closed-type plating cup) in the present invention.

[0023]FIG. 3 shows a partial enlarged view of FIG. 2 at a portion of aring-shaped seal member.

[0024] FIGS. 4(a) and 4(b) show a plating layer formation step of achemical processing method (or a plating method) of the presentinvention.

[0025] FIGS. 5(a) through 5(d) show an another embodiment of chemicalprocessing method ( or plating layer formation method) in the presentinvention.

[0026]FIG. 6 is a view showing the overall configuration of a chemicalprocessing system (or a plating system) according to a third embodimentof the present invention.

[0027]FIG. 7 is a view showing the overall configuration of a chemicalprocessing system (or a plating system) according to a fourth embodimentof the present invention.

[0028]FIG. 8 is a view showing the overall configuration of a chemicalprocessing system (or a plating system) according to a fifth embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] First Embodiment

[0030]FIG. 1 is a view showing the overall configuration of a platingsystem according to the present invention. The plating system comprisesa closed plating cup 10; a reservoir tank 20 for reserving a platingfluid; a pump 30 for supplying a plating fluid to the closed plating cup10; and a plating fluid circulation path 40 including the plating cup10, the reservoir tank 20, and the pump 30.

[0031] The closed plating cup 10 is provided with a set of plating fluidcirculation ports 10 a and 10 b in communication with an internalprocessing chamber of the cup 10. Here, the plating fluid circulationport 10 a constitutes a plating fluid supply port, and the plating fluidcirculation port 10 b constitutes a plating fluid outlet port. Thereservoir tank 20 has a plating fluid inlet port 20 a and a platingfluid outlet port 20 b. Further, the pump 30 has a plating fluid outletport 30 a and a plating port inlet port 30 b. The plating fluid outletport 30 a of the pump 30 is connected to the plating fluid supply port10 a of the closed plating cup 10 by means of a pipe 41. The pipe 41constitutes a channel for supplying a plating fluid to the closedplating cup 10. The plating fluid outlet port 10 b of the closed platingfluid cup 10 is connected to the plating fluid inlet port 20 a of thereservoir tank 20 by means of the pipe 42. The pipe 42 constitutes aplating fluid outlet channel of the closed plating cup 10. The platingfluid outlet port 20 b of the reservoir tank 20 is connected to theinlet port 30 b of the pump 30. Plating fluid 60 is stored in thereservoir tank 20 and circulated in the plating system.

[0032]FIG. 2 shows an embodiment of the closed plating cup 10. Theclosed plating cup 10 has an upper cup 110 and a lower cup 120. Theupper cup 110 and the lower cup 120 constitute a closed processingchamber 130. A lower portion of the upper cup 110 is opened, and theplating fluid circulation port 10 a is provided in substantially theupper center of the upper cup 110. Further, the plating fluidcirculation port 10 b is provided on either side of the plating fluidcirculation port 10 a. A plating fluid squirting section 111 is formedfrom a cylindrical member having an opened lower portion. A platingfluid squirting plate 113 having a plurality of plating fluid squirtingholes 112 is provided at the open end of the plating fluid squirtingsection 111. Further, the plating fluid squirting plate 113 has a meshanode electrode 114. A drain pipe 115 is provided in a lower portion ofthe upper cup 110 for collecting plating fluid or discharging washwater. The lower end of the plating fluid squirting section 111 isspaced away from and disposed opposite a top surface of a member 50 tobe plated, with an interstice “d” provided there between. The hydraulicpressure within the cup 10 can be changed by means of changing theinterstice “d.”

[0033] The lower cup 120 is formed in the shape of a plate and iscombined with the upper cup 110 so as to close the bottom of the uppercup 110. A depression 121 on which the member 50 is to be mounted isformed in the center of the lower cup 120. The member 50 is, forexample, a semiconductor wafer or a printed board. A ring-shaped sealmember 122 is provided between an outer periphery of an upper surface ofthe member 50 and the bottom surface of the upper cup 110, therebysealing the processing chamber 130 so as to prevent leakage of platingfluid from the processing chamber 130. A similar ring-shaped auxiliaryseal member 123 is provided around and outside the seal member 122. Theauxiliary seal member 123 is sandwiched between the bottom surface ofthe upper cup 110 and the lower cup 120.

[0034] As shown in FIG. 3 in an enlarged manner, the ring-shaped sealmember 122 is provided with a cathode contact 124. The cathode contact124 is a needle or wire provided so as to penetrate through thering-shaped seal member 122 in a plurality of locations. The cathodecontact 124 is in point contact with the member 50, thereby imparting acathode potential to the member 50. Although a d.c. power supply to beused for plating is not illustrated, the anode of the d.c. power supplyis connected to the mesh anode electrode 114, and the cathode of thed.c. power supply is connected to the cathode contact 124. A release 116of the seal member 122 for squirting a gas or pure water is provided onthe bottom of the upper cup 110. The release 116 is in communicationwith a supply source of gas or pure water.

[0035] FIGS. 4(a) and 4(b) show a plating layer formation step of aplating method for plating the member 50 through use of the platingsystem according to the first embodiment, to thereby form a platinglayer. FIGS. 4(a) and 4(b) also show a plating process of a method ofmanufacturing a semiconductor device. The member 50 which is to undergothe plating process corresponds to, e.g., a semiconductor wafer. Themember 50 includes a semiconductor substrate 51 formed from, e.g.,silicon or gallium arsenide. The semiconductor substrate 51 includes aplurality of semiconductor substrate portions. FIGS. 4(a) and 4(b) showtwo semiconductor substrate sections 51A and 51B separated from eachother by means of a phantom line. In a completed semiconductor device,the semiconductor substrate portions 51A and 51B are separatedindividually from each other along the phantom line. The thus-separatedsemiconductor substrate portions 51A and 51B are to become semiconductorsubstrates of respective semiconductor devices, the substrates beingcalled chips. Reference numeral 60 designates a plating fluid.

[0036] In relation to the semiconductor wafer 50, a blind hole 53 whichis to become a via hole is formed in each of the semiconductor substrateportions 51A and 51B. The semiconductor wafer 50 undergoes plating whilea lower end of each of the blind holes 51 is closed and an upper end ofeach of the blind holes 51 is opened. The semiconductor wafer 50 isdisposed in a processing chamber 130 of the closed plating cup 10 suchthat an upper open end of each of the blind holes 53 is oriented upwardand comes into contact with the circulating plating fluid 60. The mannerin which the semiconductor wafer 50 is disposed such that the upper endof each of the blind holes 53 is oriented up is called the face-upstyle.

[0037] As compared with a facedown style in which the open end of eachof the blind holes 53 is oriented downward, the face-up style is moreeffective for diminishing the amount of air bubbles developing in eachof the blind holes 53 during a plating operation. In the facedown style,the closed opening of each of the blind holes 53 is oriented upward, andhence there is a high risk of air bubbles being captured in the blindholes 53.

[0038] A thin feeding layer 54 is formed beforehand on the top of thesemiconductor wafer 50, including interior surfaces 53 a of the blindholes 53. A cathode potential is applied to the feeding layer 54 fromthe cathode contact 124. Consequently, a plating layer 70 is formed onthe feeding layer 54. After completion of the plating operation, thebottom of the semiconductor wafer 50 is eliminated by means of, e.g.,abrasion, until the respective via holes 52 become through holes. Asshown in FIGS. 5(a) through 5(d), when via holes are formed after thesemiconductor wafer 50 has been made thin, the semiconductor wafer 50 ismade thin before formation of via holes through abrasion.

[0039] Even in the face-up plating system, air bubbles 61 sometimedevelop and remain in the blind holes 53. In relation to thesemiconductor wafer 50 in which via holes having a high aspect ratio areformed, the width of the blind hole 53 becomes smaller and the depth ofthe same becomes greater. Hence, there is increased the risk of the airbubbles 61 developing and remaining in the blind holes 53. In FIG. 4(a),an air bubble 61 develops in a left-side blind hole 53. If the airbubble 61 remains during a plating operation, a plating failure 71arises, as shown in FIG. 4(b).

[0040] When a plating layer 70 made of gold (Au) is formed on thesemiconductor wafer 50 for med from GaAs, a sulfurous-acid-based platingfluid or a cyan-based plating fluid is used as the plating fluid 60. Forinstance, the sulfurous-acid-based plating fluid is composed primarilyof gold sodium sulfite and sodium sulfite. The cyan-based plating fluidis composed primarily of gold cyanide sulfite. During a platingoperation, the plating fluid 60 assumes a temperature ranging from 40(C.to 70(C.; for example, a recommended temperature of 50(C. or 65(C. Thedynamic viscosity of the plating fluid 60 assumes a value of, e.g., 0.6to 0.8 m2/sec.

[0041] The closed plating cup 10 is effective for imparting a certainpressure and flow rate to a plating fluid in the processing chamber 130of the cup 10. Use of the closed plating cup 10 enables a reduction inthe amount of air bubbles 61 developing and remaining in the blind holes53. Pressure applied to the plating fluid in the processing chamber 130provided in the closed plating cup 10 is set to a high value of, e.g.,1000 Pa or greater. Such a high pressure is effective for reducing thelikelihood of the air bubbles 61 arising and remaining in the blindholes 53.

[0042] In the first embodiment, a pulsating pump is used as the pump 30for supplying a plating fluid to the processing chamber 130 of theclosed plating cup 10. More specifically, a bellows pump or a diaphragmpump is used as the pulsating pump 30. A bellows pump pumps a platingfluid into the processing chamber 130 of the closed plating cup 10 bymeans of pulsating action of a bellows. The pressure and flow rate ofthe plating fluid within the processing chamber 130 change cyclically inaccordance with the cycle of pulsating action. Similarly, even in thecase of a diaphragm pump, the pressure and flow rate of the platingfluid within the processing chamber 130 change cyclically in accordancewith pulsating action of a diaphragm. In a bellows pump or a diaphragmpump, the pressure of the plating fluid in the processing chamber 130changes in a pulse-like manner in accordance with a cycle of pulsatingaction.

[0043] The plating system and the plating method, in which a pulsatingpump is used as the pump 30 to thereby cyclically change the pressureand flow rate of a plating fluid in the processing chamber 130, areeffective for diminishing the likelihood of the air bubbles 61developing and remaining in the blind holes 53. The air bubble 61remaining means that the developed air bubble 61 remains in the samelocation during a plating operation. Cyclic changes in the pressure andflow rate of the plating fluid in the processing chamber 130 ascribableto the pulsating pump 30 are effective for moving the air bubble 61 fromthe location where it has developed and for preventing the air bubble 61from remaining in the same location. The method of manufacturing asemiconductor device according to the present invention lessens thelikelihood of plating failures, which in turn improves a manufacturingyield of a semiconductor device to be manufactured by way of the platingprocess or improves the performance of a semiconductor device.

[0044] More specifically, a bellows pump is used as the pump 30, and thepressure applied to the plating fluid at the outlet port 30 a is set toa value of 0.12 MPa (mega pascals). Further, a plating fluid iscirculated at a flow rate of 13 liters/min. When the pulsating cycle ofthe bellows pump is set to 68 shots/min., plating failures ascribable tothe air bubbles 61 remaining can be solved completely. The pressure ofthe plating fluid in the processing chamber 130 is dependent on theinterstice “d” shown in FIG. 2; namely, the length of an intersticebetween the lower end of the plating fluid squirting section 11 and themember 50 to be plated. Hence, the interstice “d” is set to the valueranging from 5 to 6 millimeters.

[0045] Second Embodiment

[0046] A plating method according to the present invention is shown insequential order of steps. The plating system described in connectionwith the first embodiment is used in the plating method.

[0047] The second embodiment shows plating processes of the method ofmanufacturing a semiconductor device. The second embodiment employs asemiconductor wafer 50A in which one end of each of the blind holes 53is partially covered with a cover member. FIGS. 5(a) through 5(d) showprocesses of producing the semiconductor wafer 50A having such blindholes 53; namely, processes ranging from a plating preparation processto a plating process.

[0048]FIG. 5(a) shows a first preparation step. In this step, covermembers 55 formed from gold (Au) are bonded to a lower surface—namely,at predetermined areas on the back surface—of the semiconductorsubstrate 51, which is formed from, e.g., gallium arsenide (GaAs), andhas a thickness ranging from 30 micrometers to 150 micrometers. Thecover members 55 are attached to respective positions in which via holes52 are to be formed. FIG. 5(b) shows a second preparation step, whereina resist film 56 is formed on the upper surface of the semiconductorsubstrate 51. Openings 56 a are formed at positions on the resist film56 where the via holes 52 are to be formed. The semiconductor wafer 50Ais etched in this state, whereby the via holes 52 are formed. The viaholes 52 are formed so as to penetrate through the semiconductorsubstrate 51. Lower-end openings of the respective via holes 52 areclosed by the cover members 55, thereby constituting the blind holes 53.FIG. 5(c) shows a third preparation step, in which the resist film 56 isremoved and a thin feeding layer 54 is formed on the upper surface ofthe semiconductor substrate 51, including interior surfaces 53 a of theblind holes 53. The feeding layer 54 corresponds to a thin film which isformed from, e.g., nickel (Ni)/gold (Au), titanium (Ti)/gold (Au), orchromium (Cr)/gold (Au), by means of sputtering or electroless plating.

[0049]FIG. 5(d) shows a plating process. A plating layer 70 made of,e.g., gold (Au), is formed in the processing chamber 130 of the closedplating cup 10. During the plating process, the semiconductor substrate51 is plated while the openings of the blind holes 53 are orientedupward and remain in contact with the plating fluid circulating throughthe processing chamber 130. A pulsating pump is used as the pump 30, andthe pressure and flow rate of the plating fluid in the processingchamber 130 vary in accordance with a pulsating cycle of the pulsatingpump, thereby preventing any air bubbles 61 from remaining.

[0050] A method of manufacturing a printed board is also identical withthat shown in FIGS. 5(a) through 5(d). A printed board is formed from adielectric board. A predetermined circuit pattern is formed from acopper layer on each of a pair of principal planes. Simultaneously,through holes are formed in predetermined areas so as to penetratethrough the dielectric board. With the through holes being taken asblind holes, the printed board is plated in the same manner as shown inFIG. 5(d). Eventually, plating layers provided on the interior surfacesof the through holes electrically interconnect predetermined circuitpatterns provided on the respective principal planes. More specifically,the printed board is plated in the processing chamber 130 of the closedplating cup 10 while being oriented upward, such that the through holesformed in the board are opened at one end and closed at the other end,like the blind hole shown in FIG. 5(c). Any air bubbles that remain inthe blind holes are effectively discharged by means of pulsating actionof the pump 30, thereby lessening the likelihood of plating failures. Bymeans of the method for lessening the likelihood of plating failures, amanufacturing yield of a print board is improved, or the performance ofa printed board is improved.

[0051] Third Embodiment

[0052]FIG. 6 is a view showing the overall configuration of a platingsystem according to a third embodiment of the present invention. Theplating system according to the third embodiment is used for the platingmethod according to the present invention. Further, the plating systemis employed in plating processes of the method of manufacturing asemiconductor device and in those of the method of manufacturing aprinted board, both pertaining to the present invention. In the thirdembodiment, further improvements are made to the plating systemaccording to the first embodiment shown in FIG. 1. Elements, which arethe same as those shown in FIG. 1, are assigned the same referencenumerals. In the third embodiment, a flow-rate throttle valve 44 isattached to the plating fluid circulation port 10 b of the closedplating cup 10; that is, a plating fluid outlet port.

[0053] The flow-rate throttle valve 44 limits the flow rate of platingfluid flowing through the plating fluid outlet port 10 b of the closedplating processing cup 10, thereby increasing the internal pressure ofthe processing chamber 130 of the closed plating processing cup 10. Theflow-rate throttle valve 44 facilitates adjustment of the pressure ofplating fluid in the processing chamber 130 to a higher level. Thus, theflow-rate throttle valve 44 is effective for preventing occurrence ofplating failures, which would otherwise be caused by trapped air. Theflow-rate throttle valve 44 is not limited to the plating fluid outletport 10 b but may also be provided at the pipe 43 for interconnectingthe placing cup 10 and the fluid reservoir tank 20. Here, as thethrottle valve 44 is disposed closer to the plating fluid outlet port 10b, the plating-failure prevention effect becomes greater.

[0054] Fourth Embodiment

[0055]FIG. 7 is a view showing the overall configuration of a platingsystem according to a fourth embodiment of the present invention. Theplating system according to the fourth embodiment is used for theplating method according to the present invention. Further, the platingsystem is employed in plating processes of the method of manufacturing asemiconductor device and in those of the method of manufacturing aprinted board, both pertaining to the present invention. In the fourthembodiment, two pumps 31 and 32 are used as the pump 30 for supplying aplating fluid to the closed plating cup 10. Both the pumps 31 and 32 areof non-pulsating type. More specifically, the pumps 31 and 32 correspondto dubbed magnet pumps. The magnet pump rotates a rotor by the sameprinciple as that by which a motor rotates, thereby applying pressure toa plating fluid so as to continuously squirt the plating fluid. Incontrast to a pulsating pump, outlet ports 31 a and 32 a continuouslysquirt a plating fluid. Here, reference numeral 31 b designates an inletport of the pump 31, and 32 b designates an inlet port of the pump 32.

[0056] The pumps 31 and 32 are connected so as to supply a plating fluidto the processing chamber 130 of the closed plating cup 10 in oppositedirections. Specifically, the outlet port 31 a of the pump 31 isconnected to the plating fluid circulation port 10 a by means of thepipe 41, and the outlet port 32 a of the pump 32 is connected to theplating fluid circulation port 10 b by means of the pipe 42.Consequently, when the pump 31 is actuated, the plating fluid iscirculated through the processing chamber 130 in the directiondesignated by arrow A from the plating fluid circulation port 10 a tothe plating fluid circulation port 10 b. Further, when the pump 32 isactuated, the plating fluid is circulated through the processing chamber130 in the direction designated by arrow B from the plating fluidcirculation port 10 b to the plating fluid circulation port 10 a.

[0057] The pumps 31 and 32 are actuated alternately and intermittently.When the pump 31 is actuated, the pump 32 remains inoperative.Similarly, when the pump 32 is actuated, the pump 31 remainsinoperative. consequently, the direction in which the plating fluid iscirculated in the processing chamber 130 is cyclically reversed.Reversing the direction of circulation of the plating fluid results invarying the pressure and flow rate of a plating fluid which circulateswhile remaining in contact with the blind holes 53 of the member 50 andis effective for preventing occurrence of air bubbles in the blind holes53 and air bubbles remaining in the same. Provided that one direction ofcirculation of a plating fluid is taken as positive, the direction ofcirculation of a plating fluid in the processing chamber 130 is switchedsuch that the pressure and flow rate of the plating fluid vary greatlyfrom a positive value to a negative value. Hence, switching of thedirection of circulation of a plating fluid is effective for dischargingair bubbles from the blind holes 53.

[0058] Fifth Embodiment

[0059]FIG. 8 is a view showing the overall configuration of a platingsystem according to a fifth embodiment of the present invention. Theplating system according to the fifth embodiment is used for the platingmethod according to the present invention. Further, the plating systemis employed in plating processes of the method of manufacturing asemiconductor device and in those of the method of manufacturing aprinted board, both pertaining to the present invention. In the fifthembodiment, further improvements are made to the plating systemaccording to the fifth embodiment shown in FIG. 7. Elements which arethe same as those shown in FIG. 7 are assigned the same referencenumerals. In the fifth embodiment, the plating fluid circulation port 10a of the closed plating cup 10 is equipped with a flow-rate controlvalve 45, and the plating fluid circulation port 10 b is equipped with aflow-rate control valve 46. For instance, the flow-rate control valves45 and 46 are electromagnetic control valves and can control a flow rateelectrically. In synchronism with alternate actuation of the pumps 31and 32, the flow-rate control valves 45 and 46 control a flow rate.

[0060] When the pump 31 is actuated, the flow-rate control valve 46attached to the circulation port 10 b is taken as a flow-rate throttlevalve, thereby increasing the pressure of the plating fluid circulationport 10 b by way of which a plating fluid is drained from the processingchamber 130. In contrast, when the pump 32 is actuated, the flow-ratecontrol valve 45 attached to the circulation port 10 a is taken as aflow-rate throttle valve, thereby increasing the pressure of the platingfluid circulation port 10 b by way of which a plating fluid is drainedfrom the processing chamber 130. The flow-rate control valves 44 and 45facilitate adjustment of a plating fluid in the processing chamber 130at a higher pressure. Air bubbles are effectively discharged from theblind holes 53 by means of switching the direction of circulation of theplating fluid.

[0061] Sixth Embodiment

[0062] A sixth embodiment relates to a chemical treatment system to beused in a residual elimination processing operation for eliminatingresidues from surfaces, including interior surfaces of via holes of asemiconductor device, in an electroless plating operation for forming anelectroless-plated layer on the interior surfaces of via holes of thesemiconductor device, and in an electroless plating operation forforming an electroless-plated layer on the interior surfaces of throughholes of a printed board. The chemical treatment system according to thesixth embodiment is basically analogous to the plating system accordingto the first embodiment. By reference to FIGS. 1 through 3, there willbe given an explanation of primarily a difference between the chemicaltreatment system and the plating system.

[0063] In brief, the chemical treatment system according to the sixthembodiment differs from the plating system shown in FIGS. 1 through 3 inthat the plating fluid 60 is changed to a residue elimination fluid oran electroless plating fluid and that the member to be plated 50 ischanged to a member to be subjected to treatment. In association withthese changes, reference numerals 10 a, 10 b, 20 a, and 20 b designatetreatment fluid flow ports; and 40 designates a treatment fluidcirculation channel. For example, the member to be processed 50 is asemiconductor wafer or a printed board. The closed plating cup 10 is aclosed-type treatment cup and is substantially identical in constructionwith that shown in FIGS. 1 through 3. In the sixth embodiment, neitherthe residue elimination treatment nor the electroless plating treatmentrequire power feeding. Hence, the ring-shaped seal member 122 isremoved, and the processing chamber 130 is sealed with only theauxiliary seal member 123. In association with removal of the sealmember 122, the cathode contact 124 is also removed. Further, a meshanode electrode 114 is also removed, or no d.c. voltage is supplied tothe mesh anode electrode 114. In other respects, the chemical treatmentsystem is identical in construction with that shown in FIGS. 1 through3.

[0064] The chemical treatment system according to the sixth embodimentemploys a pulsating pump as the pump 30 in the same manner as in thefirst embodiment. For instance, a bellows pump or a diaphragm pump isused. A treatment fluid 60 is delivered to the processing chamber 130 ofthe closed processing cup 10 by means of the pump. As a result of use ofa pulsating pump, a pump pressure periodically changes in a pulse-likemanner. A flow rate of the pump also changes periodically. The pressureand flow rate of the treatment fluid 60 are set to the same pressure andflow rate as those described in connection with the first embodiment.Periodic changes in the pressure and flow rate of the treatment fluid 60prevent occurrence of buildup of air bubbles in a member to be treated;for example, at positions on a semiconductor wafer where via holes areformed or positions on a printed board where through holes are formed.Therefore, in the same manner as mentioned in connection with the firstembodiment, there can be prevented occurrence of deficiencies in aresidue elimination treatment or electroless plating treatment, whichwould otherwise be caused by buildup of air bubbles.

[0065] Seventh Embodiment

[0066] The method of eliminating residues through use of the chemicaltreatment system described in connection with the sixth embodiment willnow be described as a seventh embodiment. The residue eliminationtreatment is performed during the course of the process formanufacturing a semiconductor device shown in FIGS. 5A through 5D. Morespecifically, the residue elimination treatment is to be effected afterthe etching process shown in FIG. 5B.

[0067] In the etching process shown in FIG. 5B, via holes 52 are formedin the semiconductor substrate 51 made of gallium arsenide, by means of,for example, plasma etching or RIE. When the etching process has beencompleted, residues, such as carbon or chlorine, remain on the interiorsurfaces of the via holes 52. The residue elimination treatmentaccording to the seventh embodiment is for eliminating those residues.The residue elimination treatment is to be effected before formation ofthe closure member 55 following removal of the resist film 56.Alternatively, the residue elimination treatment may be effected for ablind hole 53 after formation of the closure member 55. Examples of theseventh embodiment will now be described.

EXAMPLE 1

[0068] The first example of the seventh embodiment employs an S710resist remover (manufactured by Tokyo Ohka Kogyo Ltd.) as a treatmentfluid 60. The treatment fluid 60 contains orthodichlorobenzene, phenol,and alkyl benzene sulfonate. The treatment fluid 60 was circulatedthrough the processing chamber 130 at the same pressure and flow rate asdescribed in Paragraph 0064 and with the same bellows pump as describedin Paragraph 0064, whereby residues were eliminated from a semiconductorsubstrate 51 placed faceup in the processing chamber 130. The fluidassumed a temperature of about 100° C. to 120° C. in the processingchamber 130, and the treatment time was set to 10 minutes. Consequently,deficiencies in residue elimination due to buildup of air bubbles arenot found.

EXAMPLE 2

[0069] In the second example of the seventh embodiment, an EKC256 resistremover (manufactured by EKC Corporation in the U.S.) was used as thetreatment fluid 60. The treatment fluid contains ethanolamine as themain ingredient. The fluid assumed a temperature of about 85° C. in theprocessing chamber 130, and the treatment time was set to 10 minutes. Inother respects, residues were eliminated under the same conditions asthose employed in the first embodiment. Consequently, deficiencies inresidue elimination due to buildup of air bubbles are not found.

[0070] Eighth Embodiment

[0071] A method for electroless deposition of a semiconductor device tobe performed by the chemical treatment system described in connectionwith the sixth embodiment is described as an eighth embodiment of thepresent invention. Electroless deposition is performed according to themethod of manufacturing a semiconductor device shown in FIGS. 5A through5D. More specifically, electroless deposition is to be performed duringthe process of forming a feeding layer 54 shown in FIG. 5C.

[0072] More specifically, a process for forming the feeding layer 54 wasperformed while the via holes 52 were closed with the closure member 55to constitute blind holes 53. The semiconductor substrate 51 was placedin the processing chamber 130 while remaining face-up. The treatmentfluid 60 was circulated through the processing chamber 130 at the samepressure and flow rate as described in the first embodiment and with thesame bellows pump as described in the first embodiment, whereby thesemiconductor substrate was subjected to electrolytic plating. Morespecifically, the electroless plating to which a semiconductor device isto be subjected in connection with the eighth embodiment is performed bymeans of effecting, in the order given, three processes; that is, apalladium activation process, an electroless plating process, and asubstitutional gold plating process.

[0073] During the palladium activation process, a palladium catalyst isimparted to the surface of the semiconductor substrate 51 to be platedand does not require use of the chemical treatment system described inconnection with the sixth embodiment. More specifically, a palladiumactivator fluid containing palladium chloride (PdCl₂) as the mainingredient is placed into a predetermined container separate from theclosed processing cup 10, and the semiconductor substrate 51 is immersedin the fluid.

[0074] During the subsequent electroless plating process,nickel—phosphorous (Ni—P), for example, is plated in a nonelectrolyticmanner. More specifically, a mixture consisting of nickel sulfate(NiSO₄) and sodium hypophosphite (NaH₂PO₄) is heated up to 60 to 90° C.The semiconductor substrate 51 that has finished undergoing palladiumactivation treatment is immersed in the mixture, thereby forming an Ni—Pplated layer to a thickness of 0.2 to 0.5 μm. During the electrolessplating process, hydrogen gas develops, and the treatment fluid in thevia holes 52 is agitated. Hence, there is no necessity of pulsating thefluid, and hence the electroless plating process is performed in avessel differing from the closed processing cup 10.

[0075] Final substitutional gold plating process is carried out by useof a chemical processing system as described in the sixth embodiment. Inthe substitutional gold plating process, the surface of the Ni—P platedlayer is substituted by gold. Example processes are given below.

EXAMPLE 1

[0076] (1) Treatment fluids

[0077] Metal supply agent: gold cyanide potassium (several grams/liter)

[0078] Stabilizer: a chelating agent, a complexing agent (tens ofgrams/liter)

[0079] Additive: trace amounts

[0080] pH: 6 to 7

[0081] Temperature of fluids in the processing chamber 130: 80 to 90° C.

[0082] (2) Plating time: 5 to 10 minutes

[0083] (3) Thickness of substituted gold plating: 0.1 μm

[0084] (4) Pulsation of a treatment fluid: circulated at the samepressure and flow rate as described in Paragraph 0064 and with the samebellows pump as described in the same paragraph

[0085] (5) Plating deficiencies: None

EXAMPLE 2

[0086] (1) Treatment fluids

[0087] Metal supply agent: gold sulfite (several grams/liter)

[0088] Stabilizer: a chelating agent, a complexing agent (tens ofgrams/liter)

[0089] Additive: trace amounts

[0090] pH: 7 to 8

[0091] Temperature of fluids in the processing chamber 130: 50 to 70° C.

[0092] (2) Plating time: 5 to 10 minutes

[0093] (3) Thickness of substituted gold plating: 0.1 μm

[0094] (4) Pulsation of a treatment fluid: circulated at the samepressure and flow rate as described in Paragraph 0064 and with the samebellows pump as described in the same paragraph

[0095] (5) Plating deficiencies: None

[0096] No planting deficiencies arose even in these examples. Aconceivable reason for this is that air bubbles have not built up inblind holes, because of pulsation of the treatment fluid.

[0097] Ninth Embodiment

[0098] A ninth embodiment relates to a method of plating a printed boardby means of an electroless plating method. Electroless plating for aprinted board is effected, after forming through holes in the printedboard, for forming an electroless plated layer on the interior surfacesof the respective through holes when the through holes are closed at oneend thereof, to constitute blind holes.

[0099] In more detail, electroless plating of a printed board iseffected in sequence of: an acid degreasing process, an acid activationprocess, a soft etching process, an acid activation process, a palladiumactivation process, an acid neutralization process, an electrolessplating process, a substitutional gold plating process, and a thick goldplating process. During the acid degreasing process, the interiorsurfaces of the through holes are degreased. During the acid activationprocess, the interior surfaces of the through holes are subjected toacid activation. During the soft etching process, the interior surfacesof the through holes are roughened with an etchant. During the palladiumactivation process, a palladium catalyst is imparted to the interiorsurfaces of the through holes in the same manner as described inconnection with the seventh embodiment. During the acid neutralizationprocess, an acid is neutralized after activation of palladium. Duringthe electroless plating process, an Ni—P plated layer is formed on theinterior surfaces of the through holes in the same manner as describedin connection with the seventh embodiment, by means of an electrolessplating method. All these processes are performed without use of thechemical treatment system described in connection with the sixthembodiment.

[0100] Both the substitutional gold plating process and the thick goldplating process are carried out through use of the chemical treatmentsystem described in connection with the sixth embodiment. Thesubstitutional gold plating process is performed in the same manner asdescribed in connection with the eighth embodiment. During the thickgold plating process, the thickness of plated gold is increased aftergold has been deposited in the substitutional gold plating process. Thethick gold plating process will now be described by reference toexamples provided below.

EXAMPLE 1

[0101] (1) Treatment fluids

[0102] Metal supply agent: gold cyanide potassium (several grams/liter)

[0103] Stabilizer: a chelating agent, a complexing agent (tens ofgrams/liter)

[0104] Reducer: several grams/liter

[0105] Additive: trace amounts

[0106] pH: 6 to 7

[0107] Temperature of fluids in the processing chamber 130: about 70° C.

[0108] (2) Plating time: 60 minutes

[0109] (3) Thickness of deposited gold plating: 0.1 μm

[0110] (4) Pulsation of a treatment fluid: circulated at the samepressure and flow rate as described in Paragraph 0064 and with the samebellows pump as described in the same paragraph

[0111] (5) Plating deficiencies: None

EXAMPLE 2

[0112] (1) Treatment fluids

[0113] Metal supply agent: gold sulfite (several grams/liter)

[0114] Stabilizer: a chelating agent, a complexing agent (tens ofgrams/liter)

[0115] Reducer: several grams/liter

[0116] Additive: trace amounts

[0117] pH: 7 to 8

[0118] Temperature of fluids in the processing chamber 130: 50 to 70° C.

[0119] (2) Plating time: 60 minutes

[0120] (3) Thickness of deposited gold plating: 0.7 μm

[0121] (4) Pulsation of a treatment fluid: circulated at the samepressure and flow rate as described in Paragraph 0064 and with the samebellows pump as described in the same paragraph

[0122] (5) Plating deficiencies: None

[0123] No planting deficiencies arose in any of the examples. Aconceivable reason for this is that air bubbles have not built up inblind holes, because of pulsation of the treatment fluid.

[0124] Tenth Embodiment

[0125] A tenth embodiment relates to a method of plating through holesof a printed board, by means of an electroless copper plating method. Inmore detail, electroless copper plating of a printed board is effectedin sequence of: an acid degreasing process, an acid activation process,a soft etching process, an acid activation process, a palladiumactivation process, an acid neutralization process, and an electrolessplating process. During the acid degreasing process, the interiorsurfaces of the through holes are degreased. During the acid activationprocess, the interior surfaces of the through holes are subjected toacid activation. During the soft etching process, the interior surfacesof the through holes are roughened with an etchant. During the palladiumactivation process, a palladium catalyst is imparted to the interiorsurfaces of the through holes in the same manner as described inconnection with the seventh embodiment. All these processes areperformed without use of the chemical treatment system described inconnection with the sixth embodiment.

[0126] During the electroless copper plating process, a Cu plated layeris formed on the interior surfaces of the through holes by means of anelectroless plating method. The process is performed through use of thechemical treatment system described in connection with the sixthembodiment. The electroless copper plating method will be described byreference to the examples provided below.

EXAMPLE 1

[0127] (1) Treatment fluids

[0128] Metal supply agent: copper sulfate (about 10 grams/liter)

[0129] Stabilizer: EDTA (about 30 grams/liter)

[0130] Reducer: formaldehyde (several milligrams/liter)

[0131] Additive: 2,2, dipyridyl (several PPM)

[0132] Additive: surfactant

[0133] pH: about 12

[0134] Temperature of fluids in the processing chamber 130: 70° C.

[0135] (2) Plating rate: 1 to 3 microns/hour

[0136] (3) Pulsation of a treatment fluid: circulated at the samepressure and flow rate as described in Paragraph 0064 and with the samebellows pump as described in the same paragraph

[0137] (4) Plating deficiencies: None

[0138] No planting deficiencies arose even in this example. Aconceivable reason for this is that air bubbles have not built up inblind holes, because of pulsation of the treatment fluid.

[0139] Other Embodiments

[0140] Any of the plating system shown in FIG. 6 that has been describedin connection with the third embodiment, the plating system shown inFIG. 7 that has been described in connection with the fourth embodiment,and the plating system shown in FIG. 8 that has been described inconnection with the fifth embodiment can be used as the chemicaltreatment system to be used for subjecting a semiconductor device toresidue elimination treatment and electroless plating treatment and usedfor subjecting a printed board to electroless plating.

[0141] In brief, in relation to the plating systems shown in FIGS. 6through 8, the plating fluid 60 is changed to a residue eliminationtreatment fluid or an electroless plating fluid; and the member to beplated 50 is changed to a member to be treated. In association withthese changes, reference numerals 10 a, 10 b, 20 a, and 20 b designatetreatment fluid flow ports; and 40 designates a treatment fluidcirculation channel. The member to be processed 50 is a semiconductorwafer or a printed board. The closed plating cup 10 is a closed-typetreatment cup and is substantially identical in construction with thatshown in FIGS. 1 through 3. In the sixth embodiment, neither the residueelimination treatment nor the electroless plating treatment requirepower feeding. Hence, the ring-shaped seal member 122 is removed, andthe processing chamber 130 is sealed with only the auxiliary seal member123. In association with removal of the seal member 122, the cathodecontact 124 is also removed. Further, the mesh anode electrode 114 isalso removed, or no d.c. voltage is supplied to the mesh anode electrode114. In other respects, the chemical treatment system is identical inconstruction with that shown in FIGS. 1 through 3.

[0142] A chemical treatment system based on the plating system shown inFIG. 6 is effective for closely regulating the pressure of the treatmentfluid in the processing chamber 130 with the flow throttle valve 44 andhas the effect of hindering occurrence of treatment failures, whichwould otherwise becaused by an air trap. In a chemical treatment systembased on the plating system shown in FIG. 7, the pumps 31, 32 areintermittently and alternately actuated. As a result, the direction inwhich the treatment fluid flows in the processing chamber 130 isperiodically reversed. The pressure and flow rate of the treatment fluidthat flows while remaining in contact with the blind holes areperiodically reversed, thereby eliminating occurrence and buildup of airbubbles in the blind holes. In a chemical treatment system based on theplating system shown in FIG. 8, when the pump 31 is actuated, the flowregulation valve 46 acts as a flow throttle valve. Further, when thepump 32 is actuated, the flow regulation valve 45 acts as a flowthrottle valve. As a result of an increase in the pressure of thetreatment fluid flow port 10 a and an increase in that of the treatmentfluid flow port 10 b, both discharging a treatment fluid, the pressureof the treatment fluid in the processing chamber 130 can be regulatedreadily. Switching of the flowing direction of the treatment fluid andeffective discharge of air bubbles from the blind holes can be effected.

[0143] As is evident from the foregoing descriptions, the platingsystems shown in FIGS. 1 through 3 can be used for electrolytic plating,and the plating systems shown in FIGS. 6 through 8 can be used forelectroless plating. Electrolytic plating is effected in the method ofmanufacturing a semiconductor device, and electroless plating iseffected in the method of manufacturing a printed board. When theplating system is used for electroless plating, the power feedingmechanism to be provided in the closed processing cup becomesunnecessary and can be eliminated. The plating systems shown in FIGS. 1through 3 and those shown in FIGS. 6 through 8 are used for eliminatingresidues in the process of manufacturing a semiconductor device. Even inthe residue elimination process, the power feeding mechanism to beprovided in the closed processing cup is unnecessary and can beeliminated.

[0144] The appended claims of this application are directed to achemical processing system for processing a member through use of aclosed-type processing cup. However, the present invention includes aplating system, a method of residual elimination, a method for chemicalprocessing or a method for plating a member through use of a chemicalprocessing system or a plating system using a closed-type processing cupor a plating cup as follows.

[0145] According to one aspect of the present invention, a platingsystem comprises: a closed plating cup which plates a member to beplated by means of circulating a plating fluid in the cup at a certainpressure and flow rate; a reservoir tank for storing the plating fluid;and a pump for supplying the plating fluid from the reservoir tank tothe closed plating cup, wherein the pump cyclically changes at least thepressure or flow rate of the plating fluid in the closed plating cup.(#12)

[0146] In another aspect, in the plating system, the pump is constitutedof a pulsating pump, and the pulsating pump cyclically changes at leasteither the pressure or flow rate of the plating fluid circulating withinthe closed plating cup. (#13)

[0147] In another aspect, in the plating system, the pulsating pump isconstituted of a bellows pump, and the bellows pump cyclically pulsatesthe bellows, to thereby supply the plating fluid to the closed platingcup and to cyclically change at least either the pressure or flow rateof the plating fluid circulating within the closed plating cup. (#14)

[0148] In another aspect, in the plating system, the pulsating pump isconstituted of a diaphragm pump, and the diaphragm of the diaphragm pumpis cyclically pulsated, to thereby supply the plating fluid to theclosed plating cup and to cyclically change at least either the pressureor flow rate of the plating fluid circulating within the closed platingcup. (#15)

[0149] In another aspect, the plating system further comprises a supplychannel for supplying the plating fluid to the closed plating cup, adrain channel for discharging the plating fluid from the closed platingcup, and a flow-rate throttle valve provided in the drain channel fordischarging the plating fluid. (#16)

[0150] According to one aspect of the present invention, a platingsystem comprises a closed plating cup which plates a member to be platedby means of circulating a plating fluid in the cup at a certain pressureand flow rate; a reservoir tank for storing the plating fluid; and apump for supplying the plating fluid from the reservoir tank to theclosed plating cup, wherein the direction of circulation of the platingfluid in the closed plating cup is cyclically changed. (#17)

[0151] In another aspect, in the plating system, the closed plating cuphas first and second plating circulation ports; the pump comprises firstand second pumps; the first pump circulates a plating fluid within theclosed plating cup from the first plating fluid circulation port to thesecond plating fluid circulation port; and the second pump circulatesthe plating fluid from the second plating fluid circulation port to thefirst plating fluid circulation port. (#18)

[0152] In another aspect, the plating system further comprises a firstplating fluid circulation channel communicating with the first platingfluid circulation port of the closed plating cup; a second plating fluidcirculation channel communicating with the second plating fluidcirculation port of the closed plating cup; a first flow-rate controlvalve provided in the first plating fluid circulation channel; and asecond flow-rate control valve provided in the second plating fluidcirculation channel, wherein, when the plating fluid flows from thefirst plating fluid circulation port to the second plating fluidcirculation port, the second flow-rate control valve provided in thesecond plating fluid circulation channel communicates with the secondplating fluid circulation port; and, when the plating fluid flows fromthe second plating fluid circulation port to the first plating fluidcirculation port, the first flow-rate control valve provided in thefirst plating fluid circulation channel communicates with the firstplating fluid circulation port. (#19)

[0153] In another aspect, in the plating system, the member to be platedhas a plurality of blind holes, openings on one side of the blind holesbeing opened and openings on the other side of the same being closed,and is disposed in the closed plating cup such that the opened openingsof the blind holes are in contact with the circulating plating fluid,and the surface of the member, including interior surfaces of the blindholes, is plated. (#20)

[0154] In another aspect, in the plating system, the member to be platedis a semiconductor wafer; the semiconductor wafer has a plurality of viaholes, openings on one side of the via holes being opened and openingson the other side of the same being closed; the member is disposed inthe closed plating cup such that the opened openings of the via holesare in contact with the circulating plating fluid, and the surface ofthe member, including interior surfaces of the via holes, is plated.(#21)

[0155] In another aspect, in the plating system, the member to be platedis a printed board; the semiconductor wafer has a plurality of throughholes, openings on one side of the through holes being opened andopenings on the other side of the same being closed; the member isdisposed in the closed plating cup such that the opened openings of thethrough holes are in contact with the circulating plating fluid, and thesurface of the member, including interior surfaces of the through holes,is plated. (#22)

[0156] According to another aspect of the present invention, there isprovided a chemical treatment method of subjecting a surface of a memberhaving a plurality of blind holes to chemical treatment, the surfaceincluding interior surfaces of the blind holes, and the blind holesbeing closed at one end and open at the other end. The method comprises:circulating a treatment fluid in a closed plating cup at a certainpressure and flow rate; placing the member to be treated in the closedprocessing cup such that openings of the respective blind holes at oneend thereof remain in contact with the treatment fluid; and periodicallyswitching at least either pressure or flow rate of the treatment fluidcirculating within the closed processing cup. (#23)

[0157] According to another aspect of the present invention, there isprovided a chemical treatment method of subjecting a surface of a memberhaving a plurality of blind holes to chemical treatment, the surfaceincluding interior surfaces of the blind holes, and the blind holesbeing closed at one end and open at the other end. The method comprises:circulating a treatment fluid in a closed processing cup at a certainpressure and flow rate; placing the member to be treated in the closedprocessing cup such that openings of the respective blind holes at oneend thereof remain in contact with the treatment fluid; and periodicallyswitching a flowing direction of the treatment fluid circulating in theclosed processing cup. (#24)

[0158] According to another aspect of the present invention, there isprovided a method of manufacturing a semiconductor device having viaholes penetrating through a semiconductor substrate, including achemical treatment process for subjecting, to chemical treatment, asurface of the semiconductor substrate, including interior surfaces ofthe via holes. The chemical treatment process involves: circulating atreatment fluid in a closed processing cup at a certain pressure andflow rate; placing a semiconductor wafer including the semiconductorsubstrate in the closed processing cup such that openings of therespective via holes at one end thereof remain in contact with thetreatment fluid while the other ends of the via holes are closed; andperiodically switching at least either the pressure or flow rate of thetreatment fluid circulating within the closed processing cup. (#25)

[0159] According to another aspect of the present invention, there isprovided a method of manufacturing a semiconductor device having viaholes penetrating through a semiconductor substrate, including achemical treatment process for subjecting, to chemical treatment, asurface of the semiconductor substrate, including interior surfaces ofthe via holes. The chemical treatment process involves: circulating atreatment fluid in a closed processing cup at a certain pressure andflow rate; placing a semiconductor wafer including the semiconductorsubstrate in the closed processing cup such that openings of therespective via holes at one end thereof remain in contact with thetreatment fluid while the other ends of the via holes are closed; andperiodically switching a flowing direction of the treatment fluidcirculating within the closed processing cup. (#26)

[0160] According to another aspect of the present invention, there isprovided a method of manufacturing a printed board having through holespenetrating through a substrate, including a chemical treatment processfor subjecting, to chemical treatment, a surface of the substrate,including interior surfaces of the via holes. The chemical treatmentprocess involves: circulating a treatment fluid within a closedprocessing cup at a certain pressure and flow rate; placing asemiconductor wafer including the semiconductor substrate in the closedprocessing cup such that openings of the respective through holes at oneend thereof remain in contact with the treatment fluid while the otherends of the via holes are closed; and periodically switching at leasteither the pressure or flow rate of the treatment fluid circulating inthe closed processing cup. (#27)

[0161] According to another aspect of the present invention, there isprovided a method of manufacturing a printed board having through holespenetrating through a substrate, including a chemical treatment processfor subjecting, to chemical treatment, a surface of the substrate,including interior surfaces of the via holes. The chemical treatmentprocess involves: circulating a treatment fluid in a closed processingcup at a certain pressure and flow rate; placing a semiconductor waferincluding the semiconductor substrate in the closed processing cup suchthat openings of the respective through holes at one end thereof remainin contact with the treatment fluid while the other ends of the throughholes are closed; and periodically switching a flowing direction of thetreatment fluid circulating in the closed processing cup. (#28)

[0162] According to another aspect of the present invention, in aplating method under which a member to be plated having a plurality ofblind holes, openings on one side of the blind holes being opened andopenings on the other side of the same being closed, is plated such thatthe surface of the member, including interior surfaces of the respectiveblind holes, is plated, wherein the member is disposed in the closedplating cup such that openings on one side of the respective blind holesare in contact with a plating fluid by means of circulating the platingfluid within the closed plating cup at a certain pressure and flow rate,and at least either the pressure or flow rate of the plating fluidcirculating within the closed plating cup is changed cyclically. (#29)

[0163] According to another aspect of the present invention, in aplating method under which a member to be plated having a plurality ofblind holes, openings on one side of the blind holes being opened andopenings on the other side of the same being closed, is plated such thatthe surface of the member, including interior surfaces of the respectiveblind holes, is plated, wherein the member is disposed in the closedplating cup such that openings on one side of the respective blind holesare in contact with a plating fluid by means of circulating the platingfluid within the closed plating cup at a certain pressure and flow rate,and the direction of circulation of the plating fluid circulatingthrough the closed plating cup is changed cyclically. (#30)

[0164] According to another aspect of the present invention, there isprovided a method of manufacturing a semiconductor device having viaholes penetrating through a semiconductor substrate. The methodcomprises: a plating step of plating the surface of the semiconductorsubstrate, including interior surfaces of the via holes, wherein theplating step involves circulation of a plating fluid within a closedplating cup at a certain pressure and flow rate, disposition of thesemiconductor wafer including the semiconductor substrate in the closedplating cup such that openings on one side of the via holes are openedand openings on the other side of the via holes are closed and such thatthe opened openings are in contact with the plating fluid, and cyclicchange in at least the pressure or flow rate of the plating fluidcirculating within the closed plating cup. (#31)

[0165] According to another aspect of the present invention, there isprovided a method of manufacturing a semiconductor device having viaholes penetrating through a semiconductor substrate. The methodcomprises: a plating step of plating the surface of the semiconductorsubstrate, including interior surfaces of the via holes, wherein theplating step involves circulation of a plating fluid within a closedplating cup at a certain pressure and flow rate, disposition of thesemiconductor wafer including the semiconductor substrate in the closedplating cup such that openings on one side of the via holes are openedand openings on the other side of the via holes are closed and such thatthe opened openings are in contact with the plating fluid, and cyclicchange in the direction of circulation of the plating fluid circulatingwithin the closed plating cup. (#32)

[0166] According to another aspect of the present invention, there isprovided a method of manufacturing a printed board having through holespenetrating through a board. The method comprises: a plating step ofplating the surface of the board, including interior surfaces of thethrough holes, wherein the plating step involves circulation of aplating fluid within a closed plating cup at a certain pressure and flowrate, disposition of the board in the closed plating cup such thatopenings on one side of the through holes are opened and openings on theother side of the through holes are closed and such that the openedopenings are in contact with the plating fluid, and cyclic change in atleast the pressure or flow rate of the plating fluid circulating withinthe closed plating cup. (#33)

[0167] According to another aspect of the present invention, there isprovided a method of manufacturing a printed board having through holespenetrating through a board. The method comprises: a plating step ofplating the surface of the board, including interior surfaces of thethrough holes, wherein the plating step involves circulation of aplating fluid within a closed plating cup at a certain pressure and flowrate, disposition of the board in the closed plating cup such thatopenings on one side of the through holes are opened and openings on theother side of the through holes are closed and such that the openedopenings are in contact with the plating fluid, and cyclic change in thedirection of circulation of the plating fluid circulating within theclosed plating cup. (#34)

[0168] According to another aspect of the present invention, there isprovided a residue elimination method for subjecting a surface of amember to be treated, including interior surfaces of blind holes, toresidue elimination processing, the blind holes being closed at one endand open at the other end. The method includes: circulating a treatmentfluid in a closed processing cup at a certain pressure and flow rate;placing the member the closed processing cup such that openings of therespective blind holes at one end thereof remain in contact with thetreatment fluid while the other ends of the blind holes are closed; andperiodically switching at least the pressure or flow rate of thetreatment fluid circulating within the closed processing cup. (#35)

[0169] According to another aspect of the present invention, there isprovided a residue elimination method for subjecting a surface of amember to be treated, including interior surfaces of blind holes, toresidue elimination processing, the blind holes being closed at one endand open at the other end. The method includes: circulating a treatmentfluid within a closed processing cup at a certain pressure and flowrate; placing the member the closed processing cup such that openings ofthe respective blind holes at one end thereof remain in contact with thetreatment fluid while the other ends of the blind holes are closed; andperiodically switching the flowing direction of the treatment fluidcirculating within the closed processing cup. (#36)

[0170] According to another aspect of the present invention, there isprovided a method of manufacturing a semiconductor device having viaholes penetrating through a semiconductor substrate, including a residueelimination process for subjecting, to residue elimination treatment, asurface of the semiconductor substrate, including interior surfaces ofthe via holes. The chemical treatment process involves: circulating atreatment fluid in a closed processing cup at a certain pressure andflow rate; placing a semiconductor wafer including the semiconductorsubstrate in the closed processing cup such that openings of therespective via holes at one end thereof remain in contact with thetreatment fluid while the other ends of the via holes are closed; andperiodically switching at least either the pressure or flow rate of thetreatment fluid circulating in the closed processing cup. (#37)

[0171] According to another aspect of the present invention, there isprovided a method of manufacturing a semiconductor device having viaholes penetrating through a semiconductor substrate, including a residueelimination process for subjecting, to residue elimination treatment, asurface of the semiconductor substrate, including interior surfaces ofthe via holes. The chemical treatment process involves: circulating atreatment fluid in a closed processing cup at a certain pressure andflow rate; placing a semiconductor wafer including the semiconductorsubstrate in the closed processing cup such that openings of therespective via holes at one end thereof remain in contact with thetreatment fluid while the other ends of the via holes are closed; andperiodically switching a flowing direction of the treatment fluidcirculating within the closed processing cup. (#38)

[0172] The features and advantages of the present invention as describedabove may be summarized as follows.

[0173] As has been described, according to one aspect of the presentinvention, the chemical treatment system has the closed processing cupwhich subjects a member to be treated to chemical treatment whilecirculating therein a treatment fluid at a certain pressure and acertain flow rate. The pump for supplying a treatment fluid to theclosed processing cup periodically changes at least either the pressureor flow rate of the treatment fluid in the closed processing cup. As aresult, there is yielded an effect of diminishing air bubbles remainingin the member to be treated and lessening treatment failures that occuras a result of buildup of air bubbles.

[0174] In another aspect, the pump is preferably constituted of apulsating pump, and the pulsating pump is further constructed of abellows pump or a diaphragm pump. The pump supplies a treatment fluid tothe closed processing cup by means of pulsating action of the pump. In acase where at least either the pressure or flow rate of a treatmentfluid circulating through the closed processing cup is changedperiodically, at least either the pressure or flow rate of the treatmentfluid circulating through the closed processing cup by means of thepulsating pump is effectively changed. There is yielded an effect ofdiminishing the amount of air bubbles captured by a member to be treatedand lessening treatment failures that occur as a result of buildup ofair bubbles.

[0175] In another aspect, in a chemical treatment system having a flowthrottle valve provided in a channel for discharging a treatment fluidto the closed processing cup, the pressure of a treatment fluid in theclosed processing cup can be regulated closely. Further, at least eitherthe pressure or flow rate of the treatment fluid is periodicallychanged. As a result, there is effected an advantage of effectivelyreducing air bubbles remaining in the member to be treated and lesseningtreatment failures that occur as a result of buildup of air bubbles.

[0176] In another aspect, in a chemical treatment system whichperiodically changes the direction in which the treatment fluid flows inthe closed processing cup, the flow rate of the treatment fluid as wellas the direction thereof is changed drastically. As a result, there iseffected an advantage of effectively reducing air bubbles remaining inthe member to be treated and lessening treatment failures that occur asa result of buildup of air bubbles.

[0177] In another aspect, in a chemical treatment system, which uses twopumps to periodically change the direction of the treatment fluid flowsin the closed processing cup, the circulating direction of the treatmentfluid can be changed effectively. A chemical treatment system isprovided with a flow regulation valve disposed in a channel forcirculating a treatment fluid to the closed processing cup. By means ofswitching between two pumps, a flow regulation valve provided in thetreatment fluid discharge channel is caused to act as a flow throttlevalve. In such a chemical treatment system, the pressure of a treatmentfluid in the closed processing cup can be regulated closely. Further, atleast either the pressure or flow rate of the treatment fluid isperiodically changed. As a result, there is effected an advantage ofeffectively reducing air bubbles remaining in the member to be treatedand lessening treatment failures that occur as a result of buildup ofair bubbles.

[0178] In another aspect, a member to be treated may have a plurality ofblind holes, and the member is disposed in the closed processing cupsuch that openings of the blind holes remain in contact with a treatmentfluid, thereby subjecting a surface, including interior surfaces of theblind holes, to treatment. In this case, occurrence of buildup of airbubbles in blind holes can be prevented effectively, thereby diminishingtreatment failures that occur as a result of buildup of air bubbles.Further, a semiconductor wafer, in which openings of the via holes onone side thereof are closed, or a printed board, in which openings ofthrough holes on one side thereof are closed, is subjected to treatmentin the same manner. Similarly, buildup of air bubbles in the via holesor through holes is reduced, and treatment failures that occur as aresult of buildup of air bubbles can be diminished.

[0179] Next, according to another aspect of the present invention, theplating system may by used in an electro plating and electroless platingoperation, and has the closed plating cup which plates a member to beplated by means of circulating a plating fluid in the plating system ata certain pressure and flow rate. The pump for supplying a plating fluidto the closed plating cup cyclically changes at least either a pressureor flow rate of a plating fluid in the closed plating cup. Hence, theplating system yields an advantage of the ability to lessen thelikelihood of air bubbles remaining on the member and the likelihood ofplating failures ascribable to air bubbles that remain.

[0180] In another aspect, the pump is constituted of a pulsating pump,and the pulsating pump is constituted of a bellows pump or a diaphragmpump. A plating fluid is supplied to the closed plating cup by means ofpulsating action of the pump, thereby cyclically changing at leasteither a pressure or flow rate of the plating fluid circulating throughthe inside of the closed plating cup. At least either a pressure of flowrate of the plating fluid circulating through the inside of the closedplating cup is effectively changed by means of the pulsating pump.Hence, there is yielded an advantage of the ability to lessen the amountof air bubbles remaining on a member to be plated and the likelihood ofplating failures ascribable to air bubbles that remain.

[0181] In another aspect, in the case of the plating system equippedwith a flow-rate throttle valve attached to a channel by way of which aplating fluid is discharged from the closed plating cup, the pressure ofa plating fluid circulating through the inside of the closed plating cupcan be adjusted at a higher level. There is yielded an advantage of theability to effectively lessen the amount of air bubbles that remain onthe member and the likelihood of air bubbles remaining, by means ofcyclic changes in at least either a pressure or flow rate of a platingfluid.

[0182] In another aspect, when the direction of circulation of a platingfluid circulating through the inside of the closed plating cup iscyclically changed, the flow rate of the plating fluid as well as thedirection of the same is changed greatly. Hence, there is yielded anadvantage of the ability to effectively lessen the amount of air bubblesthat remain on the member and the likelihood of plating failuresascribable to air bubbles that remain.

[0183] In another aspect, when the direction of circulation of a platingfluid in the closed plating cup is cyclically changed through use of twopumps, the direction of circulation of a plating fluid can be changedeffectively. A flow-rate control valve is provided in each of theplating fluid circulation channels of the closed cup plating cup. Inassociation with switching between the two pumps, the flow-rate controlvalve connected to a channel by way of which a plating fluid is to bedischarged is taken as a flow-rate throttle valve. As a result, thepressure of a plating fluid in the closed plating cup can be adjusted ata higher level. There is yielded an advantage of the ability toeffectively lessen the amount of air bubbles that remain on the member,by means of cyclic changes in at least either the pressure or flow rateof a plating fluid, thereby diminishing the likelihood of platingfailures ascribable to air bubbles that remain.

[0184] In another aspect, the member to be plated has a plurality ofblind holes and is disposed in the closed plating cup such that openingsof the blind holes remain in contact with a plating fluid. A platinglayer is formed on the surface of the member, including interiorsurfaces of the blind holes. As a result, air bubbles that remain in theblind holes are effectively prevented, thereby lessening the likelihoodof plating failures ascribable to air bubbles that remain. A platinglayer is formed on a semiconductor wafer having via holes, the via holesbeing closed at one end thereof, or on a printed board having via holes,the via holes being closed at one end thereof. Similarly, the amount ofair bubbles that remain in via holes or through holes is diminished,thereby lessening the likelihood of plating failures ascribable to airbubbles that remain.

[0185] Next, according to another aspect of the present invention, thechemical treatment method is a method of subjecting, to chemicaltreatment, a member which is to be subjected to treatment and has aplurality of blind holes. The method includes placing of the member in aclosed processing cup such that openings of the blind holes on one sidethereof remain in contact with a treatment fluid, and periodic changingof at least either the pressure or flow rate of a treatment fluid in theclosed processing cup. There is an advantage of reducing the amount ofair bubbles that are built up in the member to be processed and todiminish treatment failures that occur as a result of buildup of airbubbles.

[0186] [B 0114]

[0187] In another aspect, the chemical treatment method includingperiodic switching of the direction in which a treatment fluid flowsthrough the inside of the closed processing cup yields the effect ofreducing treatment failures that occur as a result of buildup of airbubbles, by means of drastically changing the flow rate of a treatmentfluid as well as a flowing direction thereof and diminishing the amountof air bubbles that build up in a member to be treated.

[0188] Next, according to another aspect of the present invention, themethod of manufacturing a semiconductor device includes a treatmentprocess for subjecting a surface, including interior surfaces of aplurality of via holes, to chemical treatment. The treatment processincludes placing of the member in a closed processing cup such thatopenings of the via holes on one side thereof remain in contact with atreatment fluid, and periodic changing of at least either the pressureor flow rate of the treatment fluid in the closed processing cup. Theamount of air bubbles that build up in the member to be subjected totreatment is reduced, and treatment failures that occur as a result ofbuildup of air bubbles can be diminished. Further, under the methodincluding periodic changing of the flowing direction of the treatmentfluid in the closed processing cup, the flowing direction of thetreatment fluid as well as the flow rate thereof are changeddrastically, thereby effectively reducing the amount of air bubbles thatbuild up in the blind holes and diminishing treatment failures thatoccur as a result of buildup of air bubbles. The performance of asemiconductor device and a manufacturing yield can be improved.

[0189] Next, according to another aspect of the present invention, themethod of manufacturing a printed board includes a treatment process forsubjecting a surface, including interior surfaces of a plurality ofthrough holes, to chemical treatment. The treatment process includesplacing of the member in a closed processing cup such that openings ofthe through holes on one side thereof remain in contact with a treatmentfluid, and periodic changing of at least either the pressure or flowrate of the treatment fluid in the closed processing cup. The amount ofair bubbles that build up in the member to be subjected to treatment isreduced, and treatment failures that occur as a result of buildup of airbubbles can be diminished. Further, under the method including periodicchanging of the flowing direction of the treatment fluid in the closedprocessing cup, the flowing direction of the treatment fluid as well asthe flow rate thereof are changed drastically, thereby effectivelyreducing the amount of air bubbles that build up in the through holesand diminishing treatment failures that occur as a result of buildup ofair bubbles. Thereby, the performance of a printed board and amanufacturing yield can be improved.

[0190] Next, according to another aspect of the present invention, theplating method may be adopted in an electro plating and an electrolessplating operation, and is for plating a member to be plated having aplurality of blind holes. The member is disposed in the closed platingcup such that openings of the blind holes remain in contact with aplating fluid. The method involves cyclic changes in at least either thepressure or flow rate of a plating fluid in the closed plating cup.There is yielded an advantage of the ability to lessen air bubbles thatremain on the member, thereby diminishing the likelihood of platingfailures ascribable to air bubbles that remain.

[0191] In another aspect, the plating method including cyclic switchingof the direction of circulation of a plating fluid within a closedplating cup yields an advantage of the ability to greatly change theflow rate of a plating fluid as well as the direction of circulation ofthe same, thereby effectively diminishing the amount of air bubbles thatremain on the member and lessening the likelihood of plating failuresascribable to air bubbles that remain.

[0192] Next, according to another aspect of the present invention, themethod of manufacturing a semiconductor device includes a plating stepof forming a plating layer on the surface of the member, includinginterior surfaces of a plurality of via holes. The plating step includesdisposition of the member in the closed plating cup such that openingson one side of respective via holes are in contact with a plating fluid,and cyclic changes in at least either the pressure or flow rate of aplating fluid in the closed plating cup. The plating method diminishesthe amount of air bubbles that remain on the member, thereby lesseningthe likelihood of plating failures ascribable to air bubbles thatremain. Further, the plating method involving cyclic changes in thedirection of circulation of a plating fluid in the closed plating cupenables a great change in the flow rate of a plating fluid as well as inthe direction of circulation of the same, thereby effectivelydiminishing the amount of air bubbles that remain on the member andlessening the likelihood of plating failures ascribable to air bubblesthat remain. Further, the method enables improvements in the performanceof a semiconductor device as well as in manufacturing yield of the same.

[0193] Next, according to another aspect of the present invention, themethod of manufacturing a printed board includes a plating step offorming a plating layer on the surface of the board, including interiorsurfaces of a plurality of via holes. The plating step includesdisposition of the board in the closed plating cup such that openings onone side of respective through holes are in contact with a platingfluid, and cyclic changes in at least either the pressure or flow rateof a plating fluid in the closed plating cup. The plating methoddiminishes the amount of air bubbles that remain on the member, therebylessening the likelihood of plating failures ascribable to air bubblesthat remain. Further, the plating method involving cyclic changes in thedirection of circulation of a plating fluid in the closed plating cupenables a great change in the flow rate of a plating fluid as well as inthe direction of circulation of the same, thereby effectivelydiminishing the amount of air bubbles that remain on the member andlessening the likelihood of plating failures ascribable to air bubblesthat remain. Further, the method enables improvements in the performanceof a printed board as well as in manufacturing yield of the same.

[0194] Next, according to another aspect of the present invention, theresidue elimination method is for eliminating residues from a member tobe treated having a plurality of blind holes. The method includesplacing of the member in a closed processing cup such that openings ofthe blind holes remain in contact with a treatment fluid, and periodicchanging of at least either the pressure or flow rate of the treatmentfluid in the closed processing cup. There is yielded an advantage ofreducing the amount of air bubbles that build up in the member to betreated and diminishing treatment failures that occur as a result ofbuildup of air bubbles.

[0195] In another aspect, under the residue elimination method includingperiodic changing of the flowing direction of the treatment fluid in theclosed processing cup, the flowing direction of the treatment fluid aswell as the flow rate thereof are changed drastically, thereby yieldingan advantage of effectively reducing the amount of air bubbles thatbuild up in the blind holes and diminishing treatment failures thatoccur as a result of buildup of air bubbles.

[0196] Next, according to another aspect of the present invention, themethod of manufacturing a semiconductor device includes a residueelimination process for subjecting a surface, including interiorsurfaces of a plurality of via holes, to residue elimination treatment.The residue elimination treatment process includes placing of the memberin a closed processing cup such that openings of the via holes on oneside thereof remain in contact with a treatment fluid, and periodicchanging of at least either the pressure or flow rate of the treatmentfluid in the closed processing cup. The amount of air bubbles that buildup in the member to be subjected to treatment is reduced, and treatmentfailures that occur as a result of buildup of air bubbles can bediminished. Further, under the method including periodic changing of theflowing direction of the treatment fluid within the closed processingcup, the flowing direction of the treatment fluid as well as the flowrate thereof are changed drastically, thereby effectively reducing theamount of air bubbles that build up in the via holes and diminishingtreatment failures that occur as a result of buildup of air bubbles.Thereby, the performance of a semiconductor device and a manufacturingyield can be improved.

[0197] Obviously many modifications and variations of the presentinvention are possible in the light of the above teachings. It istherefore to be understood that within the scope of the appended claimsthe invention may by practiced otherwise than as specifically described.

[0198] The entire disclosure of a Japanese Patent Application No.2001-103431, filed on Apr. 2, 2001 and a Japanese Patent Application No.2001-363086, filed on Nov. 28, 2001 including specifications, claims,drawings and summaries, on which the Convention priority of the presentapplication is based, are incorporated herein by reference in itsentirety.

What is claimed is:
 1. A chemical treatment system comprising: a closedprocessing cup which subjects a member to be treated to chemicaltreatment while circulating therein a treatment fluid at a certainpressure and a certain flow rate; a fluid reservoir tank for storing thetreatment fluid; and a pump for supplying the treatment fluid from thefluid reservoir tank to the closed processing cup, wherein the pumpperiodically changes at least either the pressure or flow rate of thetreatment fluid in the closed processing cup.
 2. The chemical treatmentsystem according to claim 1, wherein the pump is constituted of apulsating pump, and the pulsating pump periodically changes at leasteither the pressure or flow rate of the treatment fluid in the closedprocessing cup.
 3. The chemical treatment system according to claim 2,wherein the pulsating pump is constructed of a bellows pump and thebellows pump periodically pulsates a bellows, to thereby supply thetreatment fluid to the closed processing cup, thus periodically changingat least either the pressure or flow rate of the treatment fluidcirculating through the closed processing cup.
 4. The chemical treatmentsystem according to claim 2, wherein the pulsating pump is constructedof a diaphragm pump, and the diaphragm pump periodically pulsates adiaphragm, to thereby supply the treatment fluid to the closedprocessing cup, thus periodically changing at least either the pressureor flow rate of the treatment fluid circulating through the closedprocessing cup.
 5. The chemical treatment system according to claim 1,further comprising: a supply channel for supplying the treatment fluidto the closed processing cup, a discharge channel for discharging thetreatment fluid from the closed processing cup, and a flow throttlevalve provided in the discharge channel.
 6. A chemical treatment systemcomprising: a closed processing cup which subjects a member to betreated to chemical treatment while circulating therein a treatmentfluid at a certain pressure and a certain flow rate; a fluid reservoirtank for storing the treatment fluid; and a pumping apparatus forsupplying the treatment fluid from the fluid reservoir tank to theclosed processing cup, wherein the flowing direction of the treatmentfluid within the closed processing cup is periodically changed.
 7. Thechemical treatment system according to claim 6, wherein the closedprocessing cup has first and second treatment fluid flow ports, and thepumping apparatus has first and second pumps; and wherein the first pumpcirculates the treatment fluid in the closed processing cup from thefirst treatment fluid flow port to the second treatment fluid flow port,and the second pump circulates the treatment fluid in the closedprocessing cup from the second treatment fluid flow port to the firsttreatment fluid flow port.
 8. The chemical treatment system according toclaim 7, further comprising: a first treatment fluid channel to beconnected to the first treatment fluid flow port of the closedprocessing cup; a second treatment fluid channel to be connected to thesecond treatment fluid flow port of the closed processing cup; a firstflow regulation valve provided in the first treatment fluid flowchannel; and a second flow regulation valve provided in the secondtreatment fluid flow channel, wherein, when the treatment fluid flowsfrom the first treatment fluid flow port to the second treatment fluidflow port in the closed processing cup, the second flow regulation valveprovided in the second treatment fluid flow channel connected to thesecond treatment fluid flow port is taken as a flow throttle valve; andwherein, when the treatment fluid flows from the second treatment fluidflow port to the first treatment fluid flow port, the first flowregulation valve provided in the first treatment fluid flow channelconnected to the first treatment fluid flow port is taken as a flowthrottle valve.
 9. The chemical treatment system according to claim 1,wherein the member to be treated has a plurality of blind holes whichare closed at one end and open at the other end, and a surface of themember, including interior surfaces of the blind holes, is subjected tochemical treatment while the member is placed in the closed processingcup such that openings of the blind holes remain in contact with thecirculating treatment fluid.
 10. The chemical treatment system accordingto claim 1, wherein the member to be subjected to treatment is asemiconductor wafer; the semiconductor wafer has a plurality of viaholes which are closed at one end and open at the other end; and asurface of the semiconductor wafer, including interior surfaces of thevia holes, is subjected to chemical treatment while the semiconductorwafer is placed in the closed processing cup such that openings of thevia holes remain in contact with the circulating treatment fluid. 11.The chemical treatment system according to claim 1, wherein the memberto be subjected to treatment is a printed board; the printed board has aplurality of through holes which are closed at one end and open at theother end; and a surface of the semiconductor wafer, including interiorsurfaces of the throughholes, is subjected to chemical treatment whilethe semiconductor wafer is placed in the closed processing cup such thatopenings of the through holes remain in contact with the circulatingtreatment fluid.